Xylylenediamine is a compound useful as a raw material for polyamide resin, an epoxy resin curing agent, and a raw material for isocyanate compound or the like. However, it is known that xylylenediamine is apt to be changed in quality and colored due to light, heat, oxygen, or the like.
In addition, polyamide resins using xylylenediamine as a main diamine component are useful as a molding material containing a glass fiber or an inorganic filler because of their excellent mechanical performances, such as strength, elastic modulus, etc. In addition, the polyamide resins are also useful as a packaging material because of their excellent barrier properties against a gas, such as oxygen, carbon dioxide, etc. However, the polyamide resins involve such a problem that when exposed to a high-temperature atmosphere in a molten state or solid state, they are apt to be colored yellow, and their use was sometimes limited depending upon an application.
As a method for solving the above-described problem, for example, Japanese Patent Literature 2003-26797 discloses a polyamide resin resulting from polycondensation of a diamine containing xylylenediamine with a specified aliphatic dicarboxylic acid, in which a purity of the xylylenediamine used as the raw material diamine is 99.9% by weight or more and on heating the resin under a prescribed condition, a difference of a yellowness index (YI value) before and after heating is within 5.
Meanwhile, in order to improve processability or the like of a polyamide resin, it is known to add a crystal nucleating agent to the polyamide resin, thereby improving a crystallization rate (Japanese Patent Literature H11-158370). However, there is a concern that mechanical physical properties or the like of the polyamide resin are lowered depending upon the kind and use amount of the crystal nucleating agent used.